This invention relates to a carrier for oilwell equipment, and in particular to a carrier for an oilwell blowout preventer.
In the course of drilling oilwells, it is often necessary to mount a blowout preventer over the hole at ground level. The blowout preventer is a stack of hardware, including a top or annular preventer, a plurality of rams separated by adapter spools and a casing bowl for mounting the blowout preventer on the top end of the well casing. The blowout preventer is an unwieldly piece of equipment, standing approximately 20 feet high and weighing approximately 26 short tons. In the past, mounting and removal of the preventer was a cumbersome procedure, requiring the use of a low-boy and derricks or the like.
Obviously, there exists a need for a blowout preventer carrier/handler which solves the problems mentioned above. Apparatuses for handling heavy articles are disclosed, for example, by U.S. Pat. Nos. 2,872,052, which issued to L. G. Ferguson et al. on Feb. 3, 1959; 3,212,593, which issued to K. E. Reischl on Oct. 19, 1965; 3,268,093, which issued to R. W. Keiter on Aug. 23, 1966; 3,299,957, which issued to J. V. O'Neill et al. on Jan. 24, 1967; and 3,498,375, which issued to J. D. McEwen et al. on Mar. 3, 1970. However, none of the apparatuses described in these patents is suitable for handling equipment of the type described hereinbefore. The Reischl et al, Keiter and McEwen et al patents are of greatest interest, because they disclose the use of fluid actuated or hydraulic cylinders for raising and lowering various articles. The McEwen et al patent even discloses a dolly, which carries a blowout preventer in the vertical position, the dolly being movably mounted on an oilwell derrick substructure. However, as mentioned in the McEwen et al patent, the blowout preventer must be lifted from the dolly and moved into position by a travelling block.
It is readily apparent that a need exists for a carrier for a blowout preventer which carries the blowout preventer on site, without requiring the use of derricks or the like, either for loading or unloading the preventer, or for placing the preventer in position.
The object of the present invention is to provide a relatively simple apparatus for handling oilwell equipment, and in particular a carrier for carrying, mounting and demounting blowout preventers.